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Lipid suppression for brain MRI and MRSI by means of a dedicated crusher coil
Author(s) -
Boer Vincent O.,
van de Lindt Tessa,
Luijten Peter R.,
Klomp Dennis W.J.
Publication year - 2015
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25331
Subject(s) - dephasing , nuclear magnetic resonance , electromagnetic coil , signal (programming language) , crusher , excitation , scanner , relaxation (psychology) , pulse sequence , coherence (philosophical gambling strategy) , acoustics , physics , materials science , optics , computer science , biology , neuroscience , quantum mechanics , metallurgy , programming language
Purpose Lipid suppression in MR brain imaging and spectroscopy has been a long‐standing problem for which various techniques have been developed. Most methods are based on inversion recovery or spatially or spectrally selective excitation of the lipid signal followed by dephasing. All techniques require additional RF pulses, gradient crushers and delays, which increase the duration and complexity of sequences. In addition, the lipid signal is poorly shimmed, and is composed of different resonance frequencies that have different relaxation properties. Methods In this work, a novel approach for suppression of extra cranial lipids is presented, by means of an outer volume crusher coil. It is based on the principle of surface spoiling gradients, which generate a very local and inhomogeneous magnetic field in the outer layer of the head, and thereby destroys the phase coherence of the extra cranial signals. Results Dephasing of the signal can be incorporated in almost any sequence because it requires only a short pulse of the coil, and does not require additional RF pulses or delays. Examples of lipid suppression are shown in both gradient echo imaging and spectroscopic imaging. Conclusion Outer volume crushing allows for simple fat suppression and boosts scanning efficiency, which is particularly beneficial at ultra‐high field strengths. Magn Reson Med 73:2062–2068, 2015. © 2014 Wiley Periodicals, Inc.